DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Grating-based holographic diffraction methods for X-rays and neutrons: phase object approximation and dynamical theory

Journal Article · · Journal of Applied Crystallography (Online)
ORCiD logo [1]; ORCiD logo [2];  [3];  [3]; ORCiD logo [4]; ORCiD logo [4]; ORCiD logo [5]
  1. Indiana Univ., Bloomington, IN (United States). Center for Exploration of Energy and Matter and Physics Dept.
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division
  3. Rutherford Appleton Lab., Oxford (United Kingdom). ISIS Facility
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science
  5. Indiana Univ., Bloomington, IN (United States). Center for Exploration of Energy and Matter and Physics Dept. ; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Sciences Directorate

A method dubbed grating-based holography was recently used to determine the structure of colloidal fluids in the rectangular grooves of a diffraction grating from X-ray scattering measurements. Similar grating-based measurements have also been recently made with neutrons using a technique called spin-echo small-angle neutron scattering. The analysis of the X-ray diffraction data was done using an approximation that treats the X-ray phase change caused by the colloidal structure as a small perturbation to the overall phase pattern generated by the grating. In this paper, the adequacy of this weak phase approximation is explored for both X-ray and neutron grating holography. Additionally, it is found that there are several approximations hidden within the weak phase approximation that can lead to incorrect conclusions from experiments. In particular, the phase contrast for the empty grating is a critical parameter. Finally, while the approximation is found to be perfectly adequate for X-ray grating holography experiments performed to date, it cannot be applied to similar neutron experiments because the latter technique requires much deeper grating channels.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
Grant/Contract Number:
AC05-00OR22725; FG02-09ER46279
OSTI ID:
1422549
Journal Information:
Journal of Applied Crystallography (Online), Vol. 51, Issue 1; ISSN 1600-5767
Publisher:
International Union of CrystallographyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 1 work
Citation information provided by
Web of Science

References (18)

Microcavity arrays for X-ray diffraction studies of ordering phenomena in confined colloid solutions journal February 2005
Drug Dissolution Chip (DDC): A Microfluidic Approach for Drug Release journal September 2011
Confinement-induced liquid ordering investigated by x-ray phase retrieval journal February 2007
The scattering of high-energy electrons. I. Feynman path-integral formulation journal January 1978
Structure of confined fluids by x-ray interferometry using diffraction gratings journal January 2008
Phase-object approximation in small-angle neutron scattering experiments on silicon gratings journal January 2007
Buckling and layering transitions in confined colloids journal August 2009
Fabrication of diffraction gratings for hard X-ray phase contrast imaging journal May 2007
Grating-based holographic X-ray diffraction: theory and application to confined fluids journal October 2009
Spin-echo small angle neutron scattering in Delft journal March 2005
A new approach for probing matter in periodic nanoconfinements using neutron scattering journal August 2014
Theory of X-ray scattering from a complex fluid confined by a nanocavity array journal May 2007
Comparison of dynamical theory and phase-object approximation for neutron scattering from periodic structures journal September 2011
Lab on a chip journal July 2006
Dynamical theory calculations of spin-echo resolved grazing-incidence scattering from a diffraction grating journal April 2010
Space-time description of neutron spin echo spectrometry journal December 1996
Real-space interpretation of spin-echo small-angle neutron scattering journal January 2003
Novel SANS instrument using Neutron Spin Echo journal July 1996

Figures / Tables (4)